Could the royal family be about to announce a new addition? (Picture: AP Photo)

With just a week to go until Prince George’s first birthday on July 22, are Kate Middleton and Prince William about to announce the arrival of a new brother or sister for the future king?

Bookmakers Coral certainly believe so and have today announced they’re suspending bets on a royal pregnancy announcement this month. The decision comes after a flurry of online bets were placed overnight, which a spokesperson for the betting site says set alarm bells ringing.

Earlier in the month, the bookies had been offering odds of about 10-1 that Kate and Wills would announce a second royal arrival during July. This was then slashed to even odds (a 50-50 chance) before betting was closed completely last night.

‘With Prince George’s first birthday just around the corner, the latest gamble strongly indicates that he could soon be joined by a little brother or sister,’ predicted the Coral spokeswoman.

‘In fact, there could even be double celebrations in the Windsor household next Tuesday,’ she went on to speculate.

Despite the fact Kate didn’t show any visible signs of pregnancy in her last public appearance at the Wimbledon final earlier this month (seriously, look at her, we’ve had bigger food babies), speculation in the press overseas has been building in recent weeks.

The most significant report has so far come from Australian magazine New Idea which claims to have been told by close friend of the Duchess, Jessica Hay, that she is expecting again and the royal couple will make an announcement ‘within weeks’. This is the same ex-school friend who confirmed Kate’s first pregnancy back in 2012.

Hay is said to have told the magazine: ‘Kate’s face is fuller like it was when she was first expecting George and she’s been changing her hair, which could be to disguise the fullness.’

Hmm, we’re not so sure about the fuller face but she has been curling her hair a bit (seriously, have we actually come to this?)

Kate pre-pregnancy announcement in 2012 vs. a few weeks ago – the same ringlets, same perfectly placed clutch? (Picture: Rex/Getty)

The couple, who were forced to announce news of Kate’s pregnancy early last time round, as she suffered from severe sickness in her first eight weeks, will presumably be hoping to keep mum for as long as possible amid the latest rumours.

Kensington Palace has so far declined to comment on the speculation.

And we can only imagine what the birthday boy’s reaction might be to news of a potential young pretender to his crown.